Fecal metabolome of the Hadza hunter-gatherers: a host-microbiome integrative view

The recent characterization of the gut microbiome of traditional rural and foraging societies allowed us to appreciate the essential co-adaptive role of the microbiome in complementing our physiology, opening up significant questions on how the microbiota changes that have occurred in industrialized urban populations may have altered the microbiota-host co-metabolic network, contributing to the growing list of Western diseases. Here, we applied a targeted metabolomics approach to profile the fecal metabolome of the Hadza of Tanzania, one of the world’s few remaining foraging populations, and compared them to the profiles of urban living Italians, as representative of people in the post-industrialized West. Data analysis shows that during the rainy season, when the diet is primarily plant-based, Hadza are characterized by a distinctive enrichment in hexoses, glycerophospholipids, sphingolipids, and acylcarnitines, while deplete in the most common natural amino acids and derivatives. Complementary to the documented unique metagenomic features of their gut microbiome, our findings on the Hadza metabolome lend support to the notion of an alternate microbiome configuration befitting of a nomadic forager lifestyle, which helps maintain metabolic homeostasis through an overall scarcity of inflammatory factors, which are instead highly represented in the Italian metabolome

Microbiome and diet

The importance of gut microbiome in influencing human health has been widely assessed. The gut microbiome may vary according to several extrinsic factors, among which diet can be considered one of the most important. Substrates provided through diet are metabolized by the gut microbiome, with the possible production of beneficial or harmful metabolites. In the past decades, dietary habits in the Western world have strongly changed, with an increase in the consumption of foods of animal origin and a decrease in the intake of fiber and complex polysaccharides. These changes in the diet impacted our microbial symbionts, possibly playing a role in the development of several diseases. The understanding of these relationships will allow, in a next future, a targeted modulation of the gut microbiome through ad hoc dietary interventions for therapeutic or preventive purposes. In this chapter, recent findings about the existing interconnections between gut microbiome, diet, and human health are discussed, highlighting possible future perspectives